Land Degradation in the Sultanate of Oman: Reasons and Intervention Measures - Combating Desertification in Asia, Africa and the Middle East - page 389

1.3.3 The Arid Dhofar Plateau

The Dhofar plateau, which is gently sloping towards the north, is dissected by
numerous wadis cutting deep and narrow incisions. Most of the area consists of
sedimentary rocks.
Soils are mostly shallow and the meager natural vegetation is under heavy
grazing.

1.3.4 Accumulation Plains

There are five accumulation plains in Oman: the Batinah plain, the Northern interior
plain, the Sawqirah plain, the Dhofar piedmont and the Salalah plain.
All these plains are bajadas formed by the accumulation of three generations
of alluvial fans and terraces. The Sawqirah plain differs somewhat from the other
accumulation plains in that the rock floor outcrops in sizeable areas.
The soils are generally deep and very gravelly to extremely gravelly in all these
accumulation plains. In the Salalah plain the soils are not gypsiferous, whereas
gypsum accumulations occur in most soils of the other accumulation plains. The
quantity of gypsum and the degree of cementation tend to increase with the age of
the soils.
Cultivation is generally found in the lower alluvial terraces wherever adequate
water resources exist. Most of these cultivated areas are in the Northern interior
plain and the Batinah, because water resources are limited in the other accumulation
plains.
Date palm, limes, alfalfa and vegetables are the main cultivated crops. Falaj
systems are the main source of irrigation water, but wells are expanding very quickly
in and around the oases.

1.3.5 Accumulation/Denudation Plains

These are old accumulation plains where dissection of the landscape by stream
erosion has exposed extensive areas of rock outcrop.
The Mirbat plain is mostly rocky, but two levels of alluvial terraces were found
in its western part. They are mostly formed of loamy gravelly deposits.
The Northeastern plain in the Sharqiya region is less rocky, but the high alluvial
terraces are extremely dissected. Soils are generally gypsiferous, but many of them
have very strong salt accumulations. These salts seem to be deposited by droplets of
seawater brought by winds.
Cultivation is very limited because of scarce water resources. Datepalm and
alfalfa are the main crops.